Abstract:
:Spin-exchange NMR techniques enable the measurement of the rates of exchange of solutes between chemically or physically distinct sites in reactions taking place at chemical equilibrium. The time scale of the events that are able to be investigated lies in the neighbourhood of 1 s. The earliest studies in this area of NMR spectroscopy involved chemical reactions in vitro but the procedures have been adapted to the study of enzyme-catalysed reactions both in vitro and in vivo, and more recently to transmembrane exchange processes. The emphasis in this review is on the various types of spin-exchange experiments, the analysis of data derived from them, estimates of uncertainty in measured rate constants, and their shortcomings. Those methods given special attention are saturation transfer, two-dimensional exchange spectroscopy (2D EXSY), the 'accordion' experiment and 'overdetermined' one-dimensional exchange spectroscopy.
journal_name
NMR Biomedjournal_title
NMR in biomedicineauthors
Kuchel PWdoi
10.1002/nbm.1940030303subject
Has Abstractpub_date
1990-06-01 00:00:00pages
102-19issue
3eissn
0952-3480issn
1099-1492journal_volume
3pub_type
杂志文章,评审abstract::Biomarkers of early response to treatment have the potential to improve cancer therapy by allowing treatment to be tailored to the individual. Alterations in lipids detected by in vivo MRS have been suggested as noninvasive biomarkers of cell stress and early indicators of cell death. An improved understanding of the ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2796
更新日期:2012-11-01 00:00:00
abstract::Raised concentrations of glucose for extended periods of time have detrimental effects on the insulin-producing beta-cell. As de novo synthesis of lipids has been observed under such conditions, it was hypothesized that newly formed lipids may preferentially contain saturated fatty acids, which in particular have been...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1197
更新日期:2008-05-01 00:00:00
abstract::Quantitative susceptibility mapping (QSM) is a recently developed MRI technique that provides a quantitative measure of tissue magnetic susceptibility. To compute tissue magnetic susceptibilities based on gradient echoes, QSM requires reliable unwrapping of the measured phase images and removal of contributions caused...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3056
更新日期:2014-02-01 00:00:00
abstract::The significance of NMR water diffusion measurements performed at short diffusion times (< 10 ms) for brain tissue is examined. An apparent restriction to diffusion for both healthy and cytotoxically edematous tissue is shown: cytotoxic edema lengthens the diffusion time at which this phenomenon is visible. The dramat...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940070703
更新日期:1994-11-01 00:00:00
abstract::Patients with different types of mucopolysaccharidoses (MPS) lack specific lysosomal enzymes, which leads to tissue accumulation and urinary excretion of glycosaminoglycans (GAGs). Since little is known about the molecular composition of the excreted GAG fragments, we used two-dimensional [1H,13C]-correlation nuclear ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.833
更新日期:2003-06-01 00:00:00
abstract::Glucose metabolism in control and estrogen stimulated rat uteri was investigated using 13C NMR spectroscopy. By employing an NMR adapted perifusion system, and developing protocols and methods based on the application of [1-13C]glucose labeling, it was possible to measure, with a temporal resolution of 10 min, the kin...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940070503
更新日期:1994-08-01 00:00:00
abstract::The cerebral blood volume (CBV) is a crucial physiological indicator of tissue viability and vascular reactivity. Thus, noninvasive CBV mapping has been of great interest. For this, ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles, including monocrystalline iron oxide nanoparticles, can be used as long-ha...
journal_title:NMR in biomedicine
pub_type: 杂志文章,评审
doi:10.1002/nbm.2885
更新日期:2013-08-01 00:00:00
abstract::The transverse relaxation rates R2 and R2* were measured at 3 T in the substantia nigra of the midbrain of adult normal human controls. The relaxation rate arising from magnetic inhomogeneities, R2', was calculated from the relationship R2* = R2 + R2'. No significant differences were found for any parameters between l...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1940080106
更新日期:1995-02-01 00:00:00
abstract::In imaging of human lungs with hyperpolarised noble gases, measurements of apparent diffusion coefficient (ADC) and relaxation time provide valuable information for the assessment of lung microstructure. In this work, a sequence was developed for interleaved acquisition of ventilation images, ADC, T(2)* and flip angle...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1710
更新日期:2012-01-01 00:00:00
abstract:INTRODUCTION:Sarcoidosis is a systemic granulomatous disease affecting in particular the respiratory tract. Cardiac magnetic resonance (CMR), including a measurement of T1 relaxation time, could potentially detect early stadia of sarcoidosis of the heart. The study aims to assess T1 mapping in the detection of early ca...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4388
更新日期:2020-11-01 00:00:00
abstract::The possibility of quantifying the superimposed signal of glutamate and glutamine (Glx) and its components by ¹H magnetic resonance spectroscopy (MRS) in the spinal cord is an exciting challenge with important clinical applications in neurological conditions. The spinal cord is a particularly difficult region of inter...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2867
更新日期:2013-03-01 00:00:00
abstract::T2 of NAA, creatine and choline-containing compounds were measured in posterior frontal white matter and occipital grey matter in 10 healthy human volunteers. Decay curves comprised signals from eight TE times ranging from 30 to 800 ms with TR 2000 ms acquired with a PRESS sequence on a 1.5 T clinical scanner. Simulat...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.916
更新日期:2005-02-01 00:00:00
abstract::In this study, mapping of ultrashort T2 and T2* of acutely isolated porcine menisci at B0 = 9.4 T was investigated. Maps of T2 were measured from a slice through the pars intermedia with a spin echo-prepared two-dimensional ultrashort-TE T2 mapping technique published previously. T2* mapping was performed by two-dimen...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2931
更新日期:2013-09-01 00:00:00
abstract::The scyllo-inositol and myo-inositol concentrations of 24 normal human subjects were measured in vivo using 1H magnetic resonance spectroscopy at 4 T. Single-voxel short-echo (TE = 15 ms) metabolite spectra were collected from the white matter region of the corona radiata. Test-retest studies performed on 10 normal su...
journal_title:NMR in biomedicine
pub_type: 临床试验,杂志文章
doi:10.1002/nbm.927
更新日期:2005-02-01 00:00:00
abstract::A number of NMR spectroscopic and microscopic MRI (microMRI) techniques were used to study proton dynamics in canine tendon and articular cartilage immersed in normal saline solution (NaCl solution) and high-concentration phosphate-buffered saline (PBS) solution. In a proton CPMG experiment on tendons, the T(2) relaxa...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1294
更新日期:2009-02-01 00:00:00
abstract::Obesity causes damage to several organs, including the brain. Recent studies have been focusing on understanding the mechanisms through which obesity affects brain structure and function using neuroimaging techniques. A functional biomarker, such as cerebral blood flow (CBF), is a powerful tool that can be used to exp...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4375
更新日期:2020-10-01 00:00:00
abstract::Chemical exchange saturation transfer (CEST) imaging of amine protons exchanging at intermediate rates and whose chemical shift is around 2 ppm may provide a means of mapping creatine. However, the quantification of this effect may be compromised by the influence of overlapping CEST signals from fast-exchanging amines...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3756
更新日期:2017-10-01 00:00:00
abstract::In this work we introduce the concept of correlation chemical shift imaging (CCSI). Novel CCSI pulse sequences are demonstrated on clinical scanners for two-dimensional Correlation Spectroscopy (COSY) and Total Correlation Spectroscopy (TOCSY) imaging experiments. To date there has been limited progress reported towar...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1730
更新日期:2012-02-01 00:00:00
abstract::A study was undertaken to determine if the vascular characteristics measured by dynamic contrast-enhanced magnetic resonance imaging (primarily permeability surface area product and extracellular-extravascular tissue volume fraction) would be beneficial in explaining the inter-lesion metabolic heterogeneity displayed ...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.675
更新日期:2000-12-01 00:00:00
abstract::A special characteristic of the brain is the usage of lactate as alternative fuel instead of glucose to preserve its energy homeostasis. This physiological function is valid for sufficient cerebral glucose supply, as well as presumably during hypoglycemia, given that exogenous lactate infusion suppresses hormonal coun...
journal_title:NMR in biomedicine
pub_type: 杂志文章,随机对照试验
doi:10.1002/nbm.4167
更新日期:2019-11-01 00:00:00
abstract::Q-ball imaging (QBI) is an imaging technique that is capable of resolving intravoxel fiber crossings; however, the signal readout based on echo-planar imaging (EPI) introduces geometric distortions in the presence of susceptibility gradients. This study proposes an imaging technique that reduces susceptibility distort...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3009
更新日期:2013-12-01 00:00:00
abstract::The detection of Parkinson's disease (PD) in its preclinical stages prior to outright neurodegeneration is essential to the development of neuroprotective therapies and could reduce the number of misdiagnosed patients. However, early diagnosis is currently hampered by lack of reliable biomarkers. (1) H magnetic resona...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.2817
更新日期:2013-01-01 00:00:00
abstract::MRS provides a valuable tool for the non-invasive detection of brain γ-aminobutyric acid (GABA) in vivo. GABAergic dysfunction has been observed in the aging cerebellum. The study of cerebellar GABA changes is of considerable interest in understanding certain age-related motor disorders. However, little is known about...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3381
更新日期:2015-10-01 00:00:00
abstract::The aim of the study was to establish the normal range and to evaluate the reproducibility of dynamic contrast enhanced MRI (DCE-MRI) parameter estimates in normal human pelvic tissues. Nineteen patients with prostate cancer, undergoing androgen deprivation treatment, had paired DCE-MRI examinations of the pelvis usin...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.732
更新日期:2002-04-01 00:00:00
abstract::Proton NMR spectroscopy of biological fluids has produced interesting results lately. We used the technique to investigate the effects of cryopreservation on primary porcine hepatocytes as successful cryopreservation of primary porcine hepatocytes is of importance to the development of bioartificial liver support syst...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.765
更新日期:2002-05-01 00:00:00
abstract::Increased lactate production through glycolysis in aerobic conditions is a hallmark of cancer. Some anticancer drugs have been designed to exploit elevated glycolysis in cancer cells. For example, lonidamine (LND) inhibits lactate transport, leading to intracellular acidification in cancer cells. Chemical exchange sat...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3287
更新日期:2015-05-01 00:00:00
abstract::Development and evaluation of new anticancer drugs are expedited when minimally invasive biomarkers of pharmacokinetic and pharmacodynamic behaviour are available. Gene-directed enzyme prodrug therapy (GDEPT) is a suicide gene therapy in which the anticancer drug is activated in the tumor by an exogenous enzyme previo...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.1375
更新日期:2009-06-01 00:00:00
abstract:PURPOSE:To investigate the feasibility of using multiple flip angles in dynamic contrast enhanced (DCE) MRI to reduce the uncertainty in estimation of intracellular water lifetime (τi ). METHODS:Numerical simulation studies were conducted to assess the uncertainty in estimation of τi using dynamic contrast enhanced MR...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4135
更新日期:2019-11-01 00:00:00
abstract::Acute kidney injury (AKI) in mice caused by sustained ischemia followed by reperfusion is associated with acute tubular necrosis and renal dysfunctional blood flow. Although the principal role of the kidney is the maintenance of acid-base balance, current imaging approaches are unable to assess this important paramete...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.3720
更新日期:2017-07-01 00:00:00
abstract::The current study aims to evaluate the feasibility of creatine (Cr) chemical exchange saturation transfer (CEST)-weighted MRI at 7 T in the human brain by optimizing the saturation pulse parameters and computing contrast using a Z-spectral fitting approach. The Cr-weighted (Cr-w) CEST contrast was computed from phanto...
journal_title:NMR in biomedicine
pub_type: 杂志文章
doi:10.1002/nbm.4176
更新日期:2019-12-01 00:00:00